Potassium Carbonate → 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole

HRID 19016Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 19016
[N+:1]([C:4]1[CH:8]=[CH:7][NH:6][N:5]=1)([O-:3])=[O:2].[CH3:9][C:10]1([CH3:27])[O:14][C@H:13]([CH2:15]OS(C2C=CC(C)=CC=2)(=O)=O)[CH2:12][O:11]1.C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O.C(OCC)(=O)C>[CH3:9][C:10]1([CH3:27])[O:14][C@H:13]([CH2:15][N:6]2[CH:7]=[CH:8][C:4]([N+:1]([O-:3])=[O:2])=[N:5]2)[CH2:12][O:11]1

Komponenten

6

Reaktionsbedingungen

Temperatur
90 °C

Versuchsvorschrift

A solution of 3-nitro-1H-pyrazole (prepared as in Example 5, 12.0 g, 106 mmol) in N,N-dimethylformamide (150 mL) was treated with toluene-4-sulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl ester (25.5 g, 89.0 mmol), and potassium carbonate (24.5 g, 178 mmol). The reaction mixture was stirred for 6 h at 90° C., under nitrogen. The reaction mixture was diluted with ethyl acetate, washed with water twice, a saturated sodium chloride solution and dried over sodium sulfate. The organic layer was concentrated, and the crude product was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 330 g, 5% to 30% ethyl acetate/hexanes) to afford 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-3-nitro-1H-pyrazole (14.5 g, 72%) as light yellow oil: LR-ES-MS m/z calculated for C9H13N3O4 [M]+ 227, observed [M+H]+ 228. 1H NMR (300 MHz, CDCl3) δ ppm 1.35 (s, 3H), 1.40 (s, 3H), 3.77 (dd, J=8.8, 5.7 Hz, 1H), 4.13 (dd, J=8.8, 6.6 Hz, 1H), 4.27 (dd, J=14.0, 6.6 Hz, 1H), 4.39 (dd, J=14.0, 3.6 Hz, 1H), 4.45-4.59 (m, 1H), 6.92 (d, J=2.4 Hz, 1H), 7.59 (d, J=2.4 Hz, 1H)

Aufarbeitung

  1. washwashed with water twice
  2. dry with materiala saturated sodium chloride solution and dried over sodium sulfate
  3. concentrationThe organic layer was concentrated
  4. customthe crude product was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 330 g, 5% to 30% ethyl acetate/hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-7cc451c997fb4548876b2a95ef76272b
Quelldatensatz
uspto-grants-2010_06
Patentnummer
US07741327B2

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